tor-webwml.git

1) ## translation metadata

2) # Revision: $Revision$

3) # Translation-Priority: 4-optional
4) 
5) #include "head.wmi" TITLE="Tor: Volunteer" CHARSET="UTF-8"
6) <div id="content" class="clearfix">
7)   <div id="breadcrumbs">

8)     <a href="<page index>">Home &raquo; </a>

9)     <a href="<page getinvolved/volunteer>">Volunteer</a>
10)   </div>

11)   <div id="maincol">

12)     <!-- PUT CONTENT AFTER THIS TAG -->
13)     <h1>A few things everyone can do now:</h1>
14)     <ol>
15)     <li>Please consider <a href="<page docs/tor-doc-relay>">running
16)     a relay</a> to help the Tor network grow.</li>

17)     <li>Do you have an Amazon account? Are you willing to spend up to $3 a

18)     month? Then spin up your own Tor <a href="<page
19)     docs/bridges>">bridge</a> in less than 10 minutes with <a

20)     href="https://cloud.torproject.org/">tor cloud</a>!</li>

21)     <li>Tell your friends! Get them to run relays. Get them to run hidden
22)     services. Get them to tell their friends.</li>
23)     <li>If you like Tor's goals, please <a href="<page donate/donate>">take a moment
24)     to donate to support further Tor development</a>. We're also looking
25)     for more sponsors &mdash; if you know any companies, NGOs, agencies,
26)     or other organizations that want anonymity / privacy / communications
27)     security, let them know about us.</li>
28)     <li>We're looking for more <a href="<page about/torusers>">good examples of Tor
29)     users and Tor use cases</a>. If you use Tor for a scenario or purpose not
30)     yet described on that page, and you're comfortable sharing it with us,
31)     we'd love to hear from you.</li>
32)     </ol>

33) 

34)     <a id="Documentation"></a>
35)     <h2><a class="anchor" href="#Documentation">Documentation</a></h2>
36)     <ol>

37)     <li>Help translate the
38) <!-- web page and -->
39)     documentation into other

40)     languages. See the <a href="<page getinvolved/translation>">translation
41)     guidelines</a> if you want to help out. We especially need Arabic or
42)     Farsi translations, for the many Tor users in censored areas.</li>
43)     <li>Evaluate and document

44)     <a href="<wiki>doc/TorifyHOWTO">our

45)     list of programs</a> that can be configured to use Tor.</li>
46)     <li>We have a huge list of <a

47)     href="<wiki>doc/SupportPrograms">potentially useful

48)     programs that interface to Tor</a>. Which ones are useful in which
49)     situations? Please help us test them out and document your results.</li>
50)     </ol>

51) 

52)     <a id="Advocacy"></a>
53)     <h2><a class="anchor" href="#Advocacy">Advocacy</a></h2>
54)     <ol>

55)     <li>Create a presentation that can be used for various user group
56) meetings around the world.</li>

57)     <li>Create a video about the positive uses of Tor, what Tor is,
58)     or how to use it.  Some have already started on <a

59)     href="https://media.torproject.org/video/">Tor's Media server</a>,

60)     <a

61)     href="http://www.howcast.com/videos/90601-How-To-Circumvent-an-Internet-Proxy">Howcast</a>,

62)     and <a href="http://www.youtube.com/thetorproject">YouTube</a>.</li>

63)     <li>Create a poster, or a set of posters, around a theme,

64)     such as "Tor for Freedom!"</li>
65)     <li>Create a t-shirt design that incorporates "<a
66)     href="https://check.torproject.org/">Congratulations! You are using
67)     Tor!</a>" in any language.</li>

68)     </ol>

69) 

70)     <a id="Projects"></a>
71)     <h2><a class="anchor" href="#Projects">Projects</a></h2>

72) 

73)     <p>
74)     Below are a list of Tor related projects we're developing and/or
75)     maintaining. Most discussions happen on IRC so if you're interested in any
76)     of these (or you have a project idea of your own), then please <a

77)     href="<page about/contact>#irc">join us in #tor-dev</a>. Don't be shy
78)     to ask questions, and don't hesitate to ask even if the main contributors
79)     aren't active at that moment.

80)     </p>

81) 

82)     <table id="projects">
83)       <tr>
84)         <th>Name</th>
85)         <th>Category</th>
86)         <th>Language</th>
87)         <th>Activity</th>
88)         <th>Contributors</th>
89)       </tr>

90) 

91)       <tr>
92)         <td><a href="#project-tor">Tor</a></td>
93)         <td>Core</td>
94)         <td>C</td>
95)         <td>Heavy</td>

96)         <td>nickm, athena, arma</td>

97)       </tr>

98) 

99)       <tr class="alt">

100)         <td>*<a href="#project-jtor">JTor</a></td>
101)         <td>Core</td>
102)         <td>Java</td>
103)         <td>None</td>
104)         <td>bleidl</td>
105)       </tr>
106) 
107)       <tr>

108)         <td><a href="#project-torbrowser">Tor Browser</a></td>

109)         <td>Bundle</td>

110)         <td>C, Scripting</td>

111)         <td>Moderate</td>

112)         <td>mikeperry, Erinn</td>

113)       </tr>

114) 

115)       <tr class="alt">

116)         <td><a href="#project-torbutton">Torbutton</a></td>
117)         <td>Browser Add-on</td>
118)         <td>Javascript</td>
119)         <td>Moderate</td>
120)         <td>mikeperry</td>

121)       </tr>

122) 

123)       <tr>

124)         <td><a href="#project-httpseverywhere">HTTPS Everywhere</a></td>
125)         <td>Browser Add-on</td>
126)         <td>Javascript</td>
127)         <td>Moderate</td>
128)         <td>pde, mikeperry</td>

129)       </tr>

130) 

131)       <tr class="alt">

132)         <td><a href="#project-vidalia">Vidalia</a></td>
133)         <td>User Interface</td>
134)         <td>C++, Qt</td>

135)         <td>None</td>

136)         <td>chiiph</td>
137)       </tr>

138) 

139)       <tr>

140)         <td><a href="#project-arm">Arm</a></td>
141)         <td>User Interface</td>
142)         <td>Python, Curses</td>

143)         <td>Light</td>

144)         <td>atagar</td>
145)       </tr>

146) 

147)       <tr class="alt">

148)         <td><a href="#project-orbot">Orbot</a></td>
149)         <td>User Interface</td>
150)         <td>Java</td>

151)         <td>Light</td>

152)         <td>n8fr8</td>

153)       </tr>

154) 

155)       <tr>

156)         <td><a href="#project-tails">Tails</a></td>
157)         <td>OS image</td>
158)         <td>Sys Admin</td>
159)         <td>Heavy</td>
160)         <td><a href="https://tails.boum.org/">#tails</a></td>

161)       </tr>

162) 

163)       <tr class="alt">

164)         <td><a href="#project-torramdisk">tor-ramdisk</a></td>
165)         <td>OS image</td>
166)         <td>Sys Admin</td>
167)         <td>Light</td>
168)         <td>blueness</td>
169)       </tr>
170) 

171)       <tr>

172)         <td>*<a href="#project-torouter">Torouter</a></td>
173)         <td>OS image</td>
174)         <td>Sys Admin</td>

175)         <td>None</td>

176)         <td>ioerror</td>
177)       </tr>
178) 

179)       <tr class="alt">

180)         <td><a href="#project-torsocks">Torsocks</a></td>
181)         <td>Usability</td>
182)         <td>C</td>

183)         <td>Light</td>

184)         <td>ioerror, nickm</td>
185)       </tr>
186) 

187)       <tr>

188)         <td><a href="#project-torbirdy">TorBirdy</a></td>
189)         <td>Browser Add-on</td>
190)         <td>JavaScript</td>
191)         <td>Heavy</td>
192)         <td>Sukhbir (sukhe), ioerror</td>
193)       </tr>

194) 

195)       <tr class="alt">

196)         <td><a href="#project-obfsproxy">Obfsproxy</a></td>
197)         <td>Client Add-on</td>

198)         <td>C, Python</td>
199)         <td>Moderate</td>
200)         <td>asn, nickm</td>

201)       </tr>
202) 

203)       <tr>

204)         <td><a href="#project-flash-proxy">Flash Proxy</a></td>
205)         <td>Client Add-on</td>
206)         <td>Python, JavaScript, Go</td>

207)         <td>Heavy</td>

208)         <td>dcf, aallai, jct</td>
209)       </tr>

210) 

211)       <tr class="alt">

212)         <td>*<a href="#project-thandy">Thandy</a></td>
213)         <td>Updater</td>
214)         <td>Python</td>

215)         <td>None</td>

216)         <td>chiiph, Erinn, nickm</td>

217)       </tr>

218) 

219)       <tr>

220)         <td><a href="#project-shadow">Shadow</a></td>

221)         <td>Simulator</td>

222)         <td>C, Python</td>

223)         <td>Heavy</td>

224)         <td>robgjansen</td>
225)       </tr>

226) 

227)       <tr class="alt">

228)         <td><a href="#project-stem">Stem</a></td>

229)         <td>Library</td>
230)         <td>Python</td>
231)         <td>Heavy</td>

232)         <td>atagar</td>

233)       </tr>

234) 

235)       <tr>

236)         <td><a href="#project-txtorcon">Txtorcon</a></td>
237)         <td>Library</td>
238)         <td>Python, Twisted</td>

239)         <td>Heavy</td>

240)         <td>meejah</td>
241)       </tr>

242) 

243)       <tr class="alt">

244)         <td><a href="#project-tlsdate">Tlsdate</a></td>
245)         <td>Utility</td>
246)         <td>C</td>

247)         <td>Moderate</td>

248)         <td>ioerror</td>
249)       </tr>

250) 

251)       <tr>

252)         <td><a href="#project-metrics">Metrics</a></td>
253)         <td>Client Service</td>
254)         <td>Java</td>
255)         <td>Heavy</td>
256)         <td>karsten</td>
257)       </tr>

258) 

259)       <tr class="alt">

260)         <td><a href="#project-atlas">Atlas</a></td>
261)         <td>Client Service</td>
262)         <td>JavaScript</td>

263)         <td>Light</td>

264)         <td>hellais, karsten</td>

265)       </tr>

266) 

267)       <tr>

268)         <td><a href="#project-torstatus">TorStatus</a></td>
269)         <td>Client Service</td>

270)         <td>Python, Django</td>

271)         <td>None</td>
272)         <td></td>
273)       </tr>

274) 

275)       <tr class="alt">

276)         <td><a href="#project-compass">Compass</a></td>
277)         <td>Client Service</td>
278)         <td>Python</td>

279)         <td>Light</td>

280)         <td>gsathya, karsten, cwacek</td>

281)       </tr>

282) 

283)       <tr>

284)         <td><a href="#project-onionoo">Onionoo</a></td>
285)         <td>Backend Service</td>
286)         <td>Java, Python</td>

287)         <td>Light</td>

288)         <td>karsten, gsathya</td>
289)       </tr>
290) 

291)       <tr class="alt">

292)         <td><a href="#project-weather">Weather</a></td>
293)         <td>Client Service</td>
294)         <td>Python</td>

295)         <td>None</td>

296)         <td>kaner</td>
297)       </tr>

298) 

299)       <tr>

300)         <td><a href="#project-gettor">GetTor</a></td>
301)         <td>Client Service</td>
302)         <td>Python</td>

303)         <td>None</td>

304)         <td>kaner</td>

305)       </tr>

306) 

307)       <tr class="alt">

308)         <td><a href="#project-torcheck">TorCheck</a></td>
309)         <td>Client Service</td>
310)         <td>Python, Perl</td>
311)         <td>None</td>

312)         <td>ioerror</td>

313)       </tr>

314) 

315)       <tr>

316)         <td><a href="#project-bridgedb">BridgeDB</a></td>
317)         <td>Backend Service</td>
318)         <td>Python</td>

319)         <td>None</td>

320)         <td>kaner, nickm</td>

321)       </tr>

322) 

323)       <tr class="alt">

324)         <td><a href="#project-ooni-probe">Ooni Probe</a></td>

325)         <td>Scanner</td>
326)         <td>Python</td>

327)         <td>Heavy</td>

328)         <td>hellais, isis, ioerror</td>
329)       </tr>
330) 

331)       <tr>

332)         <td><a href="#project-torflow">TorFlow</a></td>
333)         <td>Backend Service</td>
334)         <td>Python</td>

335)         <td>None</td>

336)         <td>aagbsn, mikeperry</td>

337)       </tr>

338) 

339)       <tr class="alt">

340)         <td>*<a href="#project-torbel">TorBEL</a></td>
341)         <td>Backend Service</td>
342)         <td>Python</td>
343)         <td>None</td>
344)         <td>Sebastian</td>
345)       </tr>

346) 

347)       <tr>

348)         <td><a href="#project-tor2web">Tor2web</a></td>
349)         <td>Client Service</td>

350)         <td>Python</td>

351)         <td>Moderate</td>

352)         <td>hellais</td>

353)       </tr>

354) 

355)       <tr class="alt">

356)         <td><a href="#project-anonbib">Anonbib</a></td>
357)         <td>Website</td>

358)         <td>Python</td>

359)         <td>Light</td>
360)         <td>arma, nickm</td>
361)       </tr>
362) 

363)     </table>

364) 

365)     <sub>
366)     * Project is still in an alpha state.
367)     </sub>

368) 

369)     <br /><br />

370) 

371)     <a id="project-tor"></a>
372)     <h3>Tor (<a href="https://gitweb.torproject.org/tor.git">code</a>, <a

373)     href="https://trac.torproject.org/projects/tor/report/12">bug

374)     tracker</a>)</h3>

375) 

376)     <p>
377)     Central project, providing the core software for using and participating in
378)     the Tor network. Numerous people contribute to the project to varying
379)     extents, but the chief architects are Nick Mathewson and Roger Dingledine.
380)     </p>

381) 

382)     <p>
383)     <b>Project Ideas:</b><br />

384)     <i><a href="#limitCapabilities">Run With Limited Capabilities</a></i><br />
385)     <i><a href="#torCleanup">Tor Codebase Cleanup</a></i><br />

386)     <i><a href="#httpsImpersonation">HTTPS Server Impersonation</a></i><br />

387)     <i><a href="#chutneyExpansion">Make Chutney Do More, More Reliably</a></i>

388)     </p>

389) 

390)     <a id="project-jtor"></a>
391)     <h3><a href="https://github.com/brl/JTor/wiki">JTor</a> (<a

392)     href="https://gitweb.torproject.org/jtor.git">code</a>, <a

393)     href="https://github.com/brl/JTor/issues">bug
394)     tracker</a>)</h3>

395) 

396)     <p>
397)     Java implementation of Tor and successor to <a
398)     href="http://onioncoffee.sourceforge.net/">OnionCoffee</a>. This project
399)     isn't yet complete, and has been inactive since Fall 2010.
400)     </p>

401) 

402)     <a id="project-torbrowser"></a>

403)     <h3><a href="<page projects/torbrowser>">Tor Browser Bundle</a> (<a
404)     href="https://gitweb.torproject.org/torbrowser.git">code</a>, <a
405)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+bundles/installation&order=priority">bug

406)     tracker</a>, <a href="https://www.torproject.org/projects/torbrowser/design/">design doc</a>)</h3>
407) 

408)     <p>
409)     The Tor Browser Bundle is an easy-to-use portable package of Tor, Vidalia,

410)     Torbutton, and a Firefox fork preconfigured to work together out of

411)     the box. It contains a modified copy of Firefox that aims to resolve the
412)     privacy and security issues in mainline version.

413)     </p>

414) 
415)     <a id="project-torbutton"></a>
416)     <h3><a href="<page torbutton/index>">Torbutton</a> (<a
417)     href="https://gitweb.torproject.org/torbutton.git">code</a>, <a
418)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torbutton&order=priority">bug

419)     tracker</a>)</h3>

420) 

421)     <p>

422)     Firefox addon that addresses many of the client-side threats to browsing
423)     the Internet anonymously. Mike has since continued to adapt it to new
424)     threats, updated versions of Firefox, and possibly <a
425)     href="https://blog.torproject.org/blog/google-chrome-incognito-mode-tor-and-fingerprinting">Chrome
426)     as well</a>.

427)     </p>

428) 
429)     <a id="project-httpseverywhere"></a>
430)     <h3><a href="https://www.eff.org/https-everywhere">HTTPS Everywhere</a> (<a
431)     href="https://gitweb.torproject.org/https-everywhere.git">code</a>, <a
432)     href="https://trac.torproject.org/projects/tor/report/19">bug

433)     tracker</a>)</h3>

434) 

435)     <p>

436)     HTTPS Everywhere is a Firefox and Chrome extension that encrypts
437)     your communications with many major websites, making your browsing
438)     more secure.

439)     </p>

440) 

441)     <a id="project-vidalia"></a>
442)     <h3><a href="<page projects/vidalia>">Vidalia</a> (<a

443)     href="https://gitweb.torproject.org/vidalia.git">code</a>, <a

444)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Vidalia&order=priority">bug
445)     tracker</a>)</h3>

446) 

447)     <p>
448)     The most commonly used user interface for Tor. Matt Edman started the
449)     project in 2006 and brought it to its current stable state. Development

450)     slowed for several years, though Tomás Touceda has since taken the
451)     lead with pushing the project forward.

452)     </p>

453) 

454)     <a id="project-arm"></a>
455)     <h3><a href="http://www.atagar.com/arm/">Arm</a> (<a

456)     href="https://gitweb.torproject.org/arm.git">code</a>, <a

457)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=arm&order=priority">bug
458)     tracker</a>)</h3>

459) 

460)     <p>

461)     The anonymizing relay monitor (arm) is a terminal status monitor for Tor,
462)     intended for command-line aficionados, ssh connections, and anyone with a
463)     tty terminal. This works much like top does for system usage, providing
464)     real time statistics for bandwidth, resource usage, connections, and quite
465)     a bit more.

466)     </p>

467) 

468)     <a id="project-orbot"></a>
469)     <h3><a href="https://guardianproject.info/apps/orbot/">Orbot</a> (<a

470)     href="https://gitweb.torproject.org/orbot.git">code</a>, <a

471)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Orbot&order=priority">bug
472)     tracker</a>)</h3>

473) 
474)     <p>
475)     Provides Tor on the Android platform. This was under very active
476)     development up through Fall 2010, after which things have been quiet.
477)     </p>
478) 
479)     <a id="project-tails"></a>
480)     <h3><a href="https://tails.boum.org/">The Amnesic Incognito Live System</a> (<a
481)     href="http://git.immerda.ch/?p=amnesia.git;a=summary">code</a>, <a
482)     href="https://tails.boum.org/bugs/">bug
483)     tracker</a>)</h3>
484) 
485)     <p>
486)     The Amnesic Incognito Live System is a live CD/USB distribution
487)     preconfigured so that everything is safely routed through Tor and leaves no
488)     trace on the local system. This is a merger of the Amnesia and <a
489)     href="http://www.anonymityanywhere.com/incognito/">Incognito</a> projects,
490)     and still under very active development.
491)     </p>
492) 

493)     <a id="project-torramdisk"></a>
494)     <h3><a href="http://opensource.dyc.edu/tor-ramdisk">Tor-ramdisk</a> (<a

495)     href="http://opensource.dyc.edu/gitweb/?p=tor-ramdisk.git;a=summary">code</a>, <a
496)     href="http://opensource.dyc.edu/tor-ramdisk-documentation">documentation</a>)</h3>

497) 
498)     <p>

499)     Tor-ramdisk is a uClibc-based micro Linux distribution whose sole
500)     purpose is to securely host a Tor server purely in RAM.

501)     </p>
502) 

503)     <a id="project-torouter"></a>
504)     <h3><a
505)     href="<wiki>doc/Torouter">Torouter</a> (<a

506)     href="https://gitweb.torproject.org/torouter.git">code</a>, <a

507)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torouter&order=priority">bug
508)     tracker</a>)</h3>
509) 
510)     <p>
511)     Project to provide an easy-to-use, embedded Tor instance for routers. This
512)     had high activity in late 2010, but has since been rather quiet.
513)     </p>
514) 
515)     <a id="project-torsocks"></a>
516)     <h3><a href="http://code.google.com/p/torsocks/">Torsocks</a> (<a
517)     href="https://gitweb.torproject.org/torsocks.git">code</a>, <a
518)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torify&order=priority">bug
519)     tracker</a>)</h3>
520) 

521)     <p>

522)     Utility for adapting other applications to work with Tor. Development has
523)     slowed and compatibility issues remain with some platforms, but it's
524)     otherwise feature complete.

525)     </p>

526) 

527)     <a id="project-torbirdy"></a>
528)     <h3>TorBirdy (<a
529)     href="https://github.com/ioerror/torbirdy">code</a>, <a
530)     href="https://trac.torproject.org/projects/tor/wiki/torbirdy/dev">bug
531)     tracker</a>)</h3>

532) 

533)     <p>
534)     TorBirdy is Torbutton for Thunderbird and related Mozilla mail clients.
535)     </p>

536) 

537)     <a id="project-obfsproxy"></a>

538)     <h3><a href="<page projects/obfsproxy>">Obfsproxy</a> (<a

539)     href="https://gitweb.torproject.org/obfsproxy.git">C codebase</a>, <a
540)     href="https://gitweb.torproject.org/user/asn/pyobfsproxy.git">python
541)     codebase</a>, <a

542)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Pluggable+transport&order=priority">bug
543)     tracker</a>)</h3>

544) 

545)     <p>
546)     A proxy that shapes Tor traffic, making it harder for censors to detect and

547)     block Tor. This has both a C and python implementation.

548)     </p>

549) 

550)     <a id="project-flash-proxy"></a>
551)     <h3><a href="https://crypto.stanford.edu/flashproxy/">Flash Proxy</a> (<a
552)     href="https://gitweb.torproject.org/flashproxy.git">code</a>, <a
553)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_information&status=needs_review&status=needs_revision&status=new&status=reopened&component=Flashproxy">bug
554)     tracker</a>)</h3>

555) 

556)     <p>
557)     Pluggable transport using proxies running in web browsers to defeat
558)     address-based blocking.
559)     </p>

560) 

561)     <a id="project-thandy"></a>
562)     <h3>Thandy (<a

563)     href="https://gitweb.torproject.org/thandy.git">code</a>)</h3>

564) 

565)     <p>

566)     Updater for Tor. The project <a
567)     href="http://google-opensource.blogspot.com/2009/03/thandy-secure-update-for-tor.html">began

568)     in the Summer of 2008</a> and produced a functional secure updater. The
569)     remaining steps are to deploy a Thandy repository, and integrate Thandy
570)     into one of our bundles &mdash; which requires UI changes in the bundles,
571)     Python packaging on various platforms, etc. Later interest in it was

572)     rekindled and many aspects of <a
573)     href="http://freehaven.net/~arma/tuf-ccs2010.pdf">its design</a> (including
574)     the language it'll be in) are currently in flux. This is related to <a
575)     href="https://www.updateframework.com/">TUF</a>.

576)     </p>

577) 

578)     <a id="project-shadow"></a>
579)     <h3><a href="https://shadow.cs.umn.edu/">Shadow</a> (<a
580)     href="https://github.com/shadow">code</a>, <a
581)     href="https://github.com/shadow/shadow/issues">bug
582)     tracker</a>)</h3>

583) 

584)     <p>
585)     Shadow is a discrete-event network simulator that runs the real
586)     Tor software as a plug-in. Shadow is open-source software that enables
587)     accurate, efficient, controlled, and repeatable Tor experimentation.

588)     For another simulator, see <a
589)     href="http://crysp.uwaterloo.ca/software/exptor/">ExperimenTor</a>.

590)     </p>

591) 

592)     <a id="project-stem"></a>

593)     <h3><a href="https://stem.torproject.org/">Stem</a> (<a

594)     href="https://gitweb.torproject.org/stem.git">code</a>, <a

595)     href="https://trac.torproject.org/projects/tor/wiki/doc/stem/bugs">bug

596)     tracker</a>)</h3>

597) 

598)     <p>

599)     Python controller library for scripts and controller applications using
600)     Tor.

601)     </p>

602) 

603)     <p>
604)     <b>Project Ideas:</b><br />

605)     <i><a href="#txtorcon-stemIntegration">Txtorcon/Stem Integration</a></i><br />

606)     <i><a href="#stemUsability">Stem Usability and Porting</a></i><br />
607)     <i><a href="#stemTestingForTor">Stem Tests for Tor</a></i>

608)     </p>

609) 

610)     <a id="project-txtorcon"></a>
611)     <h3>Txtorcon (<a
612)     href="https://github.com/meejah/txtorcon">code</a>, <a
613)     href="https://txtorcon.readthedocs.org">docs</a>)</h3>

614) 

615)     <p>
616)     Twisted-based asynchronous Tor control protocol implementation. Includes
617)     unit-tests, examples, state-tracking code and configuration abstraction.
618)     Used by OONI and APAF.
619)     </p>

620) 

621)     <p>
622)     <b>Project Ideas:</b><br />
623)     <i><a href="#txtorcon-stemIntegration">Txtorcon/Stem Integration</a></i>
624)     </p>
625) 

626)     <a id="project-tlsdate"></a>
627)     <h3>Tlsdate (<a href="https://github.com/ioerror/tlsdate">code</a>)</h3>

628) 

629)     <p>
630)     tlsdate: secure parasitic rdate replacement
631)     </p>

632) 

633)     <p>
634)     tlsdate sets the local clock by securely connecting with TLS to remote
635)     servers and extracting the remote time out of the secure handshake. Unlike
636)     ntpdate, tlsdate uses TCP, for instance connecting to a remote HTTPS or TLS
637)     enabled service, and provides some protection against adversaries that try
638)     to feed you malicious time information.
639)     </p>

640) 

641)     <a id="project-metrics"></a>
642)     <h3><a href="https://metrics.torproject.org/">Metrics</a> (code: <a
643)     href="https://gitweb.torproject.org/metrics-db.git">db</a>, <a
644)     href="https://gitweb.torproject.org/metrics-utils.git">utils</a>, <a
645)     href="https://gitweb.torproject.org/metrics-web.git">web</a>, <a
646)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Metrics&order=priority">bug
647)     tracker</a>)</h3>

648) 

649)     <p>
650)     Processing and analytics of consensus data, provided to users via the
651)     metrics portal. This has been under active development for several years by

652)     Karsten Loesing. See also <a
653)     href="https://gitweb.torproject.org/torperf.git">TorPerf</a>.

654)     </p>

655) 

656)     <p>
657)     <b>Project Ideas:</b><br />
658)     <i><a href="#metricsSearch">Searchable Tor descriptor and Metrics data archive</a></i> (Python/Django?)
659)     </p>

660) 

661)     <a id="project-atlas"></a>
662)     <h3><a href="https://atlas.torproject.org/">Atlas</a> (<a
663)     href="https://gitweb.torproject.org/atlas.git">code</a>)</h3>

664) 

665)     <p>
666)     Atlas is a web application to discover Tor relays and bridges. It provides
667)     useful information on how relays are configured along with graphics about
668)     their past usage. This is the third evolution of the TorStatus application.
669)     </p>

670) 

671)     <a id="project-torstatus"></a>

672)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorStatus">TorStatus</a> (<a

673)     href="https://gitweb.torproject.org/torstatus.git">code</a>)</h3>

674) 

675)     <p>
676)     Portal providing an overview of the Tor network, and details on any of its
677)     current relays. Though very actively used, this project has been

678)     unmaintained for a long while. The <a
679)     href="https://svn.torproject.org/svn/torstatus/trunk/">original
680)     codebase</a> was written in PHP, and students from Wesleyan wrote the new
681)     Django counterpart.

682)     </p>

683) 

684)     <a id="project-compass"></a>
685)     <h3><a href="https://compass.torproject.org/">Compass</a> (<a
686)     href="https://gitweb.torproject.org/compass.git">code</a>, <a
687)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Compass&order=priority">bug
688)     tracker</a>)</h3>

689) 

690)     <p>
691)     Compass is a web and command line application that filters and
692)     aggregates the Tor relays based on various attributes.
693)     </p>

694) 
695)     <a id="project-onionoo"></a>
696)     <h3><a href="<page projects/onionoo>">Onionoo</a> (<a
697)     href="https://gitweb.torproject.org/onionoo.git">java codebase</a>, <a
698)     href="https://gitweb.torproject.org/pyonionoo.git">python

699)     codebase</a>, <a href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Onionoo&order=priority">bug tracker</a>)</h3>

700) 
701)     <p>
702)     Onionoo is a JSON based protocol to learn information about currently
703)     running Tor relays and bridges.
704)     </p>
705) 

706)     <a id="project-weather"></a>

707)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/Weather">Weather</a> (<a

708)     href="https://gitweb.torproject.org/weather.git">code</a>, <a
709)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+Weather&order=priority">bug
710)     tracker</a>)</h3>

711) 

712)     <p>
713)     Provides automatic notification to subscribed relay operators when their
714)     relay's unreachable. This underwent a rewrite by the <a
715)     href="http://hfoss.wesleyan.edu/">Wesleyan HFOSS team</a>, which went live
716)     in early 2011.
717)     </p>

718) 

719)     <a id="project-gettor"></a>

720)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/GetTor">GetTor</a> (<a

721)     href="https://gitweb.torproject.org/gettor.git">code</a>, <a

722)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=GetTor&order=priority">bug
723)     tracker</a>)</h3>

724) 

725)     <p>
726)     E-mail autoresponder providing Tor's packages over SMTP. This has been
727)     relatively unchanged for quite a while.
728)     </p>

729) 

730)     <a id="project-torcheck"></a>

731)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorCheck">TorCheck</a> (<a

732)     href="https://svn.torproject.org/svn/check/trunk/">code</a>, <a
733)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+Check&order=priority">bug
734)     tracker</a>)</h3>

735) 

736)     <p>
737)     Provides a simple site for determining if the visitor is using Tor or not.
738)     This has been relatively unchanged for quite a while.
739)     </p>

740) 

741)     <a id="project-bridgedb"></a>

742)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/BridgeDB">BridgeDB</a> (<a

743)     href="https://gitweb.torproject.org/bridgedb.git">code</a>, <a
744)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=BridgeDB&order=priority">bug
745)     tracker</a>)</h3>

746) 

747)     <p>
748)     Backend bridge distributor, handling the various pools they're distributed
749)     in. This was actively developed until Fall of 2010.
750)     </p>

751) 
752)     <a id="project-ooni-probe"></a>

753)     <h3><a href="https://ooni.torproject.org/">Ooni Probe</a> (<a

754)     href="https://gitweb.torproject.org/ooni-probe.git">code</a>, <a
755)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Ooni&order=priority">bug
756)     tracker</a>)</h3>
757) 
758)     <p>
759)     Censorship scanner, checking your local connection for blocked or modified
760)     content.
761)     </p>
762) 

763)     <a id="project-torflow"></a>

764)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorFlow">TorFlow</a> (<a

765)     href="https://gitweb.torproject.org/torflow.git">code</a>, <a
766)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torflow&order=priority">bug
767)     tracker</a>)</h3>

768) 

769)     <p>
770)     Library and collection of services for actively monitoring the Tor network.
771)     These include the Bandwidth Scanners (measuring throughput of relays) and
772)     SoaT (scans for malicious or misconfigured exit nodes). SoaT was last
773)     actively developed in the Summer of 2010, and the Bandwidth Scanners a few
774)     months later. Both have been under active use since then, but development
775)     has stopped.
776)     </p>

777) 

778)     <a id="project-torbel"></a>
779)     <h3><a

780)     href="https://blog.torproject.org/blog/torbel-tor-bulk-exit-list-tools">TorBEL</a> (<a
781)     href="https://gitweb.torproject.org/torbel.git">code</a>, <a

782)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=TorDNSEL/TorBEL&order=priority">bug
783)     tracker</a>)</h3>

784) 

785)     <p>
786)     The Tor Bulk Exitlist provides a method of identifying if IPs belong to
787)     exit nodes or not. This is a replacement for TorDNSEL which is a stable
788)     (though unmaintained) Haskell application for this purpose. The initial
789)     version of TorBEL was started in GSOC 2010 but since then the project has
790)     been inactive.
791)     </p>

792) 
793)     <a id="project-tor2web"></a>
794)     <h3><a
795)     href="http://wiki.tor2web.org/index.php/Main_Page">Tor2web</a> (<a
796)     href="https://github.com/globaleaks/tor2web-3.0/wiki">code</a>)</h3>
797) 
798)     <p>
799)     Tor2web allows Internet users to browse websites running in <a
800)     href="<page docs/hidden-services>">Tor hidden services</a>. It trades
801)     user anonymity for usability by allowing anonymous content to be
802)     distributed to non-anonymous users.
803)     </p>
804) 

805)     <a id="project-anonbib"></a>
806)     <h3><a
807)     href="http://freehaven.net/anonbib/">Anonymity Bibliography</a> (<a
808)     href="https://gitweb.torproject.org/anonbib.git">code</a>)</h3>
809) 
810)     <p>

811)     Anonbib is a list of important papers in the field of anonymity. It's
812)     also a set of scripts to generate the website from Latex (bibtex). If
813)     we're missing any important papers, please let us know!

814)     </p>
815) 

816)     <a id="Coding"></a>
817)     <a id="Summer"></a>

818)     <h2><a class="anchor" href="#Coding">Project Ideas</a></h2>

819) 

820)     <p>

821)     You may find some of these projects to be good ideas for <a href="<page
822)     about/gsoc>">Google Summer of Code</a> and the <a
823)     href="https://live.gnome.org/OutreachProgramForWomen">Outreach Program for
824)     Women</a>. We have labelled each idea with how useful it would be to the
825)     overall Tor project (priority), how much work we expect it would be (effort
826)     level), how much clue you should start with (skill level), and which of our
827)     <a href="<page about/corepeople>">core developers</a> would be good
828)     mentors. If one or more of these ideas looks promising to you, please <a

829)     href="<page about/contact>">contact us</a> to discuss your plans rather than
830)     sending blind applications. You may also want to propose your own project
831)     idea &mdash; which often results in the best applications.
832)     </p>

833) 

834)     <p>
835)     <b>If you came to this site for Google Summer of Code then please keep in
836)     mind that Google has not yet announced the participating organisations, and
837)     Tor might not be selected. See the <a
838)     href="https://www.google-melange.com/document/show/gsoc_program/google/gsoc2013/help_page#2._What_is_the_program_timeline">timeline</a>
839)     for more information.</b>
840)     </p>
841) 

842)     <ol>

843) 

844)     <a id="txtorcon-stemIntegration"></a>
845)     <li>
846)     <b>Txtorcon/Stem Integration</b>
847)     <br>
848)     Effort Level: <i>Medium</i>
849)     <br>
850)     Skill Level: <i>Medium</i>
851)     <br>
852)     Likely Mentors: <i>meejah, Damian (atagar)</i>
853)     <p>Txtorcon is a Twisted-based Python controller library, and Stem is a
854)     synchronous (threaded) one, also in Python. There is no need to have
855)     two implementations of (at least) the protocol parsing code. This
856)     project would entail eliminating duplication by leveraging Stem's
857)     parsing in txtorcon while keeping txtorcon's API the same (or at least
858)     close).</p>
859)     <p>This would very likely involve changes to both libraries, although
860)     most would be expected to be in txtorcon. meejah is available to
861)     mentor txtorcon changes, and Damian (atagar) can help with Stem.</p>
862)     <p>It would help if you're already familiar with event-based programming,
863)     bonus points if it's Twisted.</p>
864)     </li>
865) 

866)     <a id="httpsImpersonation"></a>

867)     <li>
868)     <b>HTTPS Server Impersonation</b>
869)     <br>
870)     Effort Level: <i>Medium to High</i>
871)     <br>
872)     Skill Level: <i>Medium to High</i>
873)     <br>
874)     Likely Mentors: <i>Nick (nickm)</i>

875)     <p>

876)     We have an open proposal for a way to make Tor bridges avoid censorship by
877)     impersonating an HTTPS server.  Specifically, we need to hack some popular
878)     SSL "reverse proxy" (your choice) so that it relays regular web connections
879)     to an HTTP server, but certain connections to a local Tor process.  <a
880)     href="https://gitweb.torproject.org/torspec.git/blob_plain/HEAD:/proposals/203-https-frontend.txt">Proposal
881)     203</a> has a general design sketch.

882)     </p>
883)     </li>

884) 

885)     <a id="chutneyExpansion"></a>
886)     <li>
887)     <b>Make Chutney Do More, More Reliably</b>
888)     <br>
889)     Effort Level: <i>Medium to High, depending on scope of project</i>
890)     <br>
891)     Skill Level: <i>Medium</i>
892)     <br>

893)     Likely Mentors: <i>Nick (nickm)</i>
894)     <p>

895)     We have a little Python tool called <a
896)     href="https://gitweb.torproject.org/nickm/chutney.git">Chutney</a> for
897)     making small local test networks.  It's small, not widely used, and not as
898)     automated as it could be.

899)     </p>

900) 

901)     <p>

902)     It would be great to see chutney extended and a set of supporting tests
903)     built to the point where we could use Chutney to exercise various Tor
904)     features as an automated integration test.

905)     </p>

906)     </li>

907) 

908)     <a id="limitCapabilities"></a>

909)     <li>

910)     <b>Run With Limited Capabilities</b>

911)     <br>
912)     Effort Level: <i>Medium to High</i>
913)     <br>

914)     Skill Level: <i>High</i>

915)     <br>
916)     Likely Mentors: <i>Nick (nickm)</i>
917)     <p>

918)     Many modern operating systems give a running program the ability to drop
919)     capabilities that it no longer needs, and other ways for a program to run
920)     pieces of itself in a sandbox with diminished privileges.

921)     </p>

922) 

923)     <p>

924)     We'd like to do this with Tor, to improve its resistance to attacks.  The
925)     easiest areas to address would be on systems like <a
926)     href="https://lwn.net/Articles/475361/">recent Linux kernels</a> that make
927)     it easy to drop or restrict the set of syscalls that a program can invoke.
928)     That's a great project, but probably not big enough for an internship just
929)     on its own.  For that, we'd want to make progress on at least multiple
930)     platforms, or look into refactoring Tor into pieces that need more
931)     privileges and pieces that don't with an eye towards sandboxing them
932)     differently.

933)     </p>

934) 

935)     <p>

936)     See tickets <a href="https://trac.torproject.org/7005">#7005</a> and <a
937)     href="https://trac.torproject.org/5219">#5219</a>, and their descendants,
938)     for more information.

939)     </p>
940)     </li>

941) 

942)     <a id="metricsSearch"></a>

943)     <li>

944)     <b>Searchable Tor descriptor and Metrics data archive</b>

945)     <br>
946)     Effort Level: <i>Medium</i>
947)     <br>
948)     Skill Level: <i>Medium</i>
949)     <br>

950)     Likely Mentors: <i>Karsten</i>
951)     <p>The <a href="https://metrics.torproject.org/data.html">Metrics data
952)     archive</a> of Tor relay descriptors and other Tor-related network data has
953)     grown to over 100G in size, bz2-compressed.  We have developed two search
954)     interfaces: the <a
955)     href="https://metrics.torproject.org/relay-search.html">relay search</a>
956)     finds relays by nickname, fingerprint, or IP address in a given month; <a
957)     href="https://metrics.torproject.org/exonerator.html">ExoneraTor</a> finds
958)     whether a given IP address was a relay on a given day.</p>

959) 

960)     <p>We'd like to have a more general search application for Tor descriptors
961)     and metrics data.  There are more <a
962)     href="https://metrics.torproject.org/formats.html">descriptor types</a>
963)     that we'd like to include in the search.  The search application should
964)     handle most of them and understand some semantics like what's a timestamp,
965)     what's an IP address, and what's a link to another descriptor.  Users
966)     should then be able to search for arbitrary strings or limit their search
967)     to given time periods or IP address ranges.  Descriptors that reference
968)     other descriptors should contain links, and descriptors should be able to
969)     say from where they are linked.  The goal is to make the archive easily
970)     browsable.</p>

971) 

972)     <p>The search application shall be separate from the metrics website and
973)     shouldn't rely on the metrics website codebase.  The search application
974)     will contain hourly updated descriptor data from the metrics website via
975)     rsync.  Programming language and database system are not specified yet,
976)     though there's a slight preference for Python/Django and Postgres for
977)     maintenance reasons.  If there are good reasons to pick something else,
978)     e.g, some NoSQL variant or some search application framework, that's fine,
979)     too.  Further requirements are that lookups should be really fast and that
980)     changes to the search application can be implemented in reasonable
981)     time.</p>

982) 

983)     <p>Applications for this project should come with a design of the proposed
984)     search application, ideally with a proof-of-concept based on a subset of
985)     the available data to show that it will be able to handle the 100G+ of
986)     data.</p>

987)     </li>

988) 

989)     <a id="stemUsability"></a>

990)     <li>

991)     <b>Stem Usability and Porting</b>

992)     <br>
993)     Effort Level: <i>Medium</i>
994)     <br>
995)     Skill Level: <i>Medium</i>
996)     <br>

997)     Likely Mentors: <i>Damian (atagar)</i>
998)     <p>

999)     <a href="https://stem.torproject.org/">Stem</a> is a

1000)     python controller library for tor. Like it's predecessor, <a

1001)     href="https://gitweb.torproject.org/pytorctl.git">TorCtl</a>, it uses tor's <a

1002)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/control-spec.txt">control
1003)     protocol</a> to help developers program against the tor process, enabling
1004)     them to build things similar to <a href="#project-vidalia">Vidalia</a> and

1005)     <a href="http://www.atagar.com/arm/">arm</a>.

1006)     </p>

1007) 

1008)     <p>
1009)     While TorCtl provided a fine first draft for this sort of functionality,
1010)     it has not proved to be extensible nor maintainable. Stem is a rewrite of
1011)     TorCtl with a heavy focus on testing, documentation, and providing a
1012)     developer friendly API.
1013)     </p>

1014) 

1015)     <p>

1016)     Stem has largely met these goals but there's still plenty of low hanging
1017)     fruit in terms of usability improvements. Also, we have clients still using
1018)     TorCtl that need to be ported over. This project includes several subtasks,
1019)     see the tickets for additional context...

1020)     </p>

1021) 

1022)     <ol>
1023)       <li>Come up with a better, more developer friendly "Module Overview" for our documentation (<a href="https://stem.torproject.org/api/control.html">example page</a>). For instance, it would be nice to provide interlinking between the overview and the classes/methods that it lists. This will probably involve asking for help from the <a href="http://sphinx-doc.org/">Sphinx user list</a>. (<a href="https://trac.torproject.org/7632">ticket</a>)</li>
1024)       <li>Navigation of <a href="https://stem.torproject.org">stem's site</a> is clunky, in large part due to the linear page flow supported by sphinx. One possible fix for this would be css-only menus, ideally as a sphinx plugin so we could contribute it back upstream.(<a href="https://trac.torproject.org/8431">ticket</a>)</li>
1025)       <li>After getting some exposure to stem it would be time to give using it a try. Tor has a couple clients (<a href="https://trac.torproject.org/8263">TorBEL</a> and <a href="https://trac.torproject.org/8264">Tor Weather</a>) that are ready to be moved to stem. Hopefully porting these will also provide us with some lessons on how we can further improve stem's API.</li>
1026)       <li><b>... other ideas?</b> The above are just some ideas I've come up with to improve usability and likely not enough to fill the summer. Feel free to suggest some of your own! For instance, one option would be to expand <a href="https://stem.torproject.org/tutorial.html">stem's tutorials</a> with more examples, maybe <a href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev/">contacting tor-dev@</a> to brainstorm ideas. This last bit is pretty open so I look forward to seeing what you come up with!</li>
1027)     </ol>

1028) 

1029)     <p>

1030)     <b>As part of your application for this project please write a script that does something interesting with stem.</b> Bonus points if this is something that we can <a href="https://stem.torproject.org/tutorial.html">make a tutorial</a> around!

1031)     </p>

1032) 

1033)     <a id="stemTestingForTor"></a>
1034)     <li>
1035)     <b>Stem Tests for Tor</b>
1036)     <br>
1037)     Effort Level: <i>Medium</i>
1038)     <br>
1039)     Skill Level: <i>Medium</i>
1040)     <br>
1041)     Likely Mentors: <i>Damian (atagar)</i>
1042)     <p>
1043)     Stem is a library for interacting with Tor (see '<a href="#stemUsability">Stem Usability and Porting</a>' above for a summary). The library has both <a href="https://gitweb.torproject.org/stem.git/tree/HEAD:/test/unit">unit</a> and <a href="https://gitweb.torproject.org/stem.git/tree/HEAD:/test/integ">integration</a> tests. The unit tests provide a quick, direct test of stem's codebase while the integration test exercises its functionality against a live instance of Tor.
1044)     </p>
1045) 
1046)     <p>
1047)     Stem's integration tests have thus far been (unsurprisingly) designed to test stem but there's no need for them to be limited to that. Stem is a complete implementation of Tor's <a href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/control-spec.txt">control-spec</a> and <a href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/dir-spec.txt">dir-spec</a>. As such, stem's tests could be easily expanded to more dedicatedly test behavior involved in those portions of Tor's codebase, as well as provide a smoke test for its general functionality.
1048)     </p>
1049) 
1050)     <p>
1051)     This project would involve several components:
1052)     </p>
1053) 
1054)     <ol>
1055)       <li>Determine what kind of tests we need. <b>This should be done during the application phase</b> by <a href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev/">contacting tor-dev@</a>. Hopefully this will give us an idea of what would be the most useful kind of tests of this nature for Tor development.</li>
1056)       <li>To be useful our integration tests need to continually run against the present tip of Tor's codebase. To do this we'll want to (1) fetch and compile the latest version of Tor, (2) run our integration tests against it, (3) compose the results as an html formatted email, and send it to a list. (<a href="https://trac.torproject.org/8261">ticket</a>)</li>
1057)       <li>Implement the new suite of integration tests for Tor. This will likely include expanding Tor to support better testability. One useful candidate, for instance, would be a controller method to fetch our own descriptor. This would let us easily test various configurations to see if they provide valid descriptor content.</li>
1058)     </ol>
1059) 
1060)     <p>
1061)     <b>As part of your application for this project please write some code to expand stem's tests.</b> Bonus points if it impelments one of your suggestions for better testing Tor!
1062)     </p>
1063) 

1064)     <a id="torCleanup"></a>

1065)     <li>

1066)     <b>Tor Codebase Cleanup</b>

1067)     <br>

1068)     Effort Level: <i>Low to High, depending on subproject chosen</i>

1069)     <br>

1070)     Skill Level: <i>Medium to High</i>

1071)     <br>

1072)     Likely Mentors: <i>Nick (nickm)</i>

1073)     <p>

1074)     The Tor code is almost 10 years old in places, and we haven't always had
1075)     enough time or wisdom to write things as well as we could have.  Our unit
1076)     test coverage is shamefully low, and the dependency graph of our modules is
1077)     shamefully convoluted . We could use refactoring and unit tests!  Please
1078)     look through the Tor source code and look for ugly or tricky code or
1079)     dependencies -- the uglier and trickier the better -- and think about how
1080)     you could make the code look better, read better, and (subject to testing)
1081)     work better.

1082)     </p>

1083) 

1084)     <p>

1085)     If this is for a fun side-project, it would be great for you to work on
1086)     anything that can be made better and more tested.  For an internship-level
1087)     position, we'd hope that you could find a number of particularly tricky or
1088)     knotty piece of the code to clean up, and aim for resolving the ugliest
1089)     problems, not necessarily the easiest.

1090)     </p>

1091) 

1092)     <p>

1093)     For a big project here, it would be great to pick one of the major
1094)     "submodules" of Tor -- path selection, node discovery, directory authority
1095)     operations, directory service -- and refactor its interface completely, to
1096)     minify and codify its points of contact with the rest of Tor.

1097)     </p>
1098)     </li>

1099) 

1100)     <li>
1101)     <b>Bring up new ideas!</b>

1102)     <br>

1103)     Don't like any of these? Look at the <a

1104)     href="/press/presskit/2008-12-19-roadmap-full.pdf">Tor development

1105)     roadmap</a> for more ideas, or just try out Tor, Vidalia, and Torbutton,
1106)     and find out what you think needs fixing.

1107)     Some of the <a href="<spectree>proposals">current proposals</a>

1108)     might also be short on developers.
1109)     </li>

1110) 

1111)     </ol>

1112) 

1113)     <a id="OtherCoding"></a>
1114)     <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>
1115)     <ol>
1116)     <li>Tor relays don't work well on Windows XP. On
1117)     Windows, Tor uses the standard <tt>select()</tt> system
1118)     call, which uses space in the non-page pool. This means
1119)     that a medium sized Tor relay will empty the non-page pool, <a

1120)     href="<wiki>doc/WindowsBufferProblems">causing

1121)     havoc and system crashes</a>. We should probably be using overlapped IO
1122)     instead. One solution would be to teach <a
1123)     href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
1124)     overlapped IO rather than select() on Windows, and then adapt Tor to
1125)     the new libevent interface. Christian King made a
1126)     <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good
1127)     start</a> on this in the summer of 2007.</li>

1128) 

1129)     <li>We need to actually start building our <a href="<page
1130)     docs/documentation>#DesignDoc">blocking-resistance design</a>. This involves
1131)     fleshing out the design, modifying many different pieces of Tor, adapting
1132)     <a href="<page projects/vidalia>">Vidalia</a> so it supports the
1133)     new features, and planning for deployment.</li>

1134) 

1135)     <li>We need a flexible simulator framework for studying end-to-end
1136)     traffic confirmation attacks. Many researchers have whipped up ad hoc
1137)     simulators to support their intuition either that the attacks work
1138)     really well or that some defense works great. Can we build a simulator
1139)     that's clearly documented and open enough that everybody knows it's
1140)     giving a reasonable answer? This will spur a lot of new research.
1141)     See the entry <a href="#Research">below</a> on confirmation attacks for
1142)     details on the research side of this task &mdash; who knows, when it's
1143)     done maybe you can help write a paper or three also.</li>

1144) 

1145)     <li>Tor 0.1.1.x and later include support for hardware crypto
1146)     accelerators via OpenSSL. It has been lightly tested and is
1147)     possibly very buggy.  We're looking for more rigorous testing,

1148)     performance analysis, and optimally, code fixes to OpenSSL and

1149)     Tor if needed.</li>

1150) 

1151)     <li>Write a <a
1152)     href="https://secure.wikimedia.org/wikipedia/en/wiki/Fuzz_testing">fuzzer</a>
1153)     for Tor to discover security vulnerabilities. Determine if there
1154)     are good fuzzing frameworks out there for what we want. Win fame by

1155)     getting credit when we put out a new release because of you!</li>

1156) 

1157)     <li>Tor uses TCP for transport and TLS for link
1158)     encryption. This is nice and simple, but it means all cells
1159)     on a link are delayed when a single packet gets dropped, and
1160)     it means we can only reasonably support TCP streams. We have a <a

1161)     href="<page docs/faq>#TransportIPnotTCP">list

1162)     of reasons why we haven't shifted to UDP transport</a>, but it would
1163)     be great to see that list get shorter. We also have a proposed <a

1164)     href="<specblob>proposals/100-tor-spec-udp.txt">specification

1165)     for Tor and
1166)     UDP</a> &mdash; please let us know what's wrong with it.</li>

1167) 

1168)     <li>We're not that far from having IPv6 support for destination addresses
1169)     (at exit nodes). If you care strongly about IPv6, that's probably the
1170)     first place to start.</li>

1171) 

1172)     <li>We need a way to generate the website diagrams (for example, the "How
1173)     Tor Works" pictures on the <a href="<page about/overview>">overview page</a>
1174)     from source, so we can translate them as UTF-8 text rather than edit
1175)     them by hand with Gimp. We might want to
1176)     integrate this as an wml file so translations are easy and images are
1177)     generated in multiple languages whenever we build the website.</li>

1178) 

1179)     <li>How can we make the various LiveCD/USB systems easier
1180)     to maintain, improve, and document?  One example is <a

1181)     href="https://tails.boum.org/">The Amnesic Incognito Live

1182)     System</a>.
1183)     </li>

1184) 

1185)     <li>
1186)     Another anti-censorship project is to try to make Tor
1187)     more scanning-resistant.  Right now, an adversary can identify <a

1188)     href="<specblob>proposals/125-bridges.txt">Tor bridges</a>

1189)     just by trying to connect to them, following the Tor protocol,
1190)     and seeing if they respond.  To solve this, bridges could <a
1191)     href="<svnprojects>design-paper/blocking.html#tth_sEc9.3">act like
1192)     webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
1193)     and not act like bridges until the user provides a bridge-specific key.
1194)     To start, check out Shane Pope's <a
1195)     href="http://dl.dropbox.com/u/37735/index.html">thesis and prototype</a>.
1196)     </li>

1197) 

1198)     </ol>

1199) 

1200)     <a id="Research"></a>
1201)     <h2><a class="anchor" href="#Research">Research</a></h2>
1202)     <ol>
1203)     <li>The "end-to-end traffic confirmation attack":
1204)     by watching traffic at Alice and at Bob, we can <a
1205)     href="http://freehaven.net/anonbib/#danezis:pet2004">compare
1206)     traffic signatures and become convinced that we're watching the same
1207)     stream</a>. So far Tor accepts this as a fact of life and assumes this
1208)     attack is trivial in all cases. First of all, is that actually true? How
1209)     much traffic of what sort of distribution is needed before the adversary
1210)     is confident he has won? Are there scenarios (e.g. not transmitting much)
1211)     that slow down the attack? Do some traffic padding or traffic shaping
1212)     schemes work better than others?</li>
1213)     <li>A related question is: Does running a relay/bridge provide additional
1214)     protection against these timing attacks? Can an external adversary that can't
1215)     see inside TLS links still recognize individual streams reliably?
1216)     Does the amount of traffic carried degrade this ability any? What if the
1217)     client-relay deliberately delayed upstream relayed traffic to create a queue
1218)     that could be used to mimic timings of client downstream traffic to make it
1219)     look like it was also relayed? This same queue could also be used for masking
1220)     timings in client upstream traffic with the techniques from <a
1221)     href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
1222)     but without the need for additional traffic. Would such an interleaving of
1223)     client upstream traffic obscure timings for external adversaries? Would the
1224)     strategies need to be adjusted for asymmetric links? For example, on
1225)     asymmetric links, is it actually possible to differentiate client traffic from
1226)     natural bursts due to their asymmetric capacity? Or is it easier than
1227)     symmetric links for some other reason?</li>
1228)     <li>Repeat Murdoch and Danezis's <a
1229)     href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
1230)     Oakland 05</a> on the current Tor network. See if you can learn why it
1231)     works well on some nodes and not well on others. (My theory is that the
1232)     fast nodes with spare capacity resist the attack better.) If that's true,
1233)     then experiment with the RelayBandwidthRate and RelayBandwidthBurst
1234)     options to run a relay that is used as a client while relaying the
1235)     attacker's traffic: as we crank down the RelayBandwidthRate, does the
1236)     attack get harder? What's the right ratio of RelayBandwidthRate to
1237)     actually capacity? Or is it a ratio at all? While we're at it, does a
1238)     much larger set of candidate relays increase the false positive rate
1239)     or other complexity for the attack? (The Tor network is now almost two
1240)     orders of magnitude larger than it was when they wrote their paper.) Be
1241)     sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
1242)     Clog the Queue</a> too.</li>
1243)     <li>The "routing zones attack": most of the literature thinks of
1244)     the network path between Alice and her entry node (and between the
1245)     exit node and Bob) as a single link on some graph. In practice,
1246)     though, the path traverses many autonomous systems (ASes), and <a
1247)     href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
1248)     that the same AS appears on both the entry path and the exit path</a>.
1249)     Unfortunately, to accurately predict whether a given Alice, entry,
1250)     exit, Bob quad will be dangerous, we need to download an entire Internet
1251)     routing zone and perform expensive operations on it. Are there practical
1252)     approximations, such as avoiding IP addresses in the same /8 network?</li>
1253)     <li>Other research questions regarding geographic diversity consider
1254)     the tradeoff between choosing an efficient circuit and choosing a random
1255)     circuit. Look at Stephen Rollyson's <a
1256)     href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
1257)     paper</a> on how to discard particularly slow choices without hurting
1258)     anonymity "too much". This line of reasoning needs more work and more
1259)     thinking, but it looks very promising.</li>
1260)     <li>Tor doesn't work very well when relays have asymmetric bandwidth
1261)     (e.g. cable or DSL). Because Tor has separate TCP connections between
1262)     each hop, if the incoming bytes are arriving just fine and the outgoing
1263)     bytes are all getting dropped on the floor, the TCP push-back mechanisms
1264)     don't really transmit this information back to the incoming streams.
1265)     Perhaps Tor should detect when it's dropping a lot of outgoing packets,
1266)     and rate-limit incoming streams to regulate this itself? I can imagine
1267)     a build-up and drop-off scheme where we pick a conservative rate-limit,
1268)     slowly increase it until we get lost packets, back off, repeat. We
1269)     need somebody who's good with networks to simulate this and help design
1270)     solutions; and/or we need to understand the extent of the performance
1271)     degradation, and use this as motivation to reconsider UDP transport.</li>
1272)     <li>A related topic is congestion control. Is our
1273)     current design sufficient once we have heavy use? Maybe
1274)     we should experiment with variable-sized windows rather
1275)     than fixed-size windows? That seemed to go well in an <a

1276)     href="http://www.psc.edu/index.php/hpn-ssh/638">ssh

1277)     throughput experiment</a>. We'll need to measure and tweak, and maybe
1278)     overhaul if the results are good.</li>
1279)     <li>Our censorship-resistance goals include preventing
1280)     an attacker who's looking at Tor traffic on the wire from <a
1281)     href="<svnprojects>design-paper/blocking.html#sec:network-fingerprint">distinguishing
1282)     it from normal SSL traffic</a>. Obviously we can't achieve perfect
1283)     steganography and still remain usable, but for a first step we'd like to
1284)     block any attacks that can win by observing only a few packets. One of
1285)     the remaining attacks we haven't examined much is that Tor cells are 512
1286)     bytes, so the traffic on the wire may well be a multiple of 512 bytes.
1287)     How much does the batching and overhead in TLS records blur this on the
1288)     wire? Do different buffer flushing strategies in Tor affect this? Could
1289)     a bit of padding help a lot, or is this an attack we must accept?</li>
1290)     <li>Tor circuits are built one hop at a time, so in theory we have the
1291)     ability to make some streams exit from the second hop, some from the
1292)     third, and so on. This seems nice because it breaks up the set of exiting
1293)     streams that a given relay can see. But if we want each stream to be safe,
1294)     the "shortest" path should be at least 3 hops long by our current logic, so
1295)     the rest will be even longer. We need to examine this performance / security
1296)     tradeoff.</li>
1297)     <li>It's not that hard to DoS Tor relays or directory authorities. Are client
1298)     puzzles the right answer? What other practical approaches are there? Bonus
1299)     if they're backward-compatible with the current Tor protocol.</li>
1300)     <li>Programs like <a

1301)     href="<page torbutton/index>">Torbutton</a> aim to hide

1302)     your browser's UserAgent string by replacing it with a uniform answer for
1303)     every Tor user. That way the attacker can't splinter Tor's anonymity set
1304)     by looking at that header. It tries to pick a string that is commonly used
1305)     by non-Tor users too, so it doesn't stand out. Question one: how badly
1306)     do we hurt ourselves by periodically updating the version of Firefox
1307)     that Torbutton claims to be? If we update it too often, we splinter the
1308)     anonymity sets ourselves. If we don't update it often enough, then all the
1309)     Tor users stand out because they claim to be running a quite old version
1310)     of Firefox. The answer here probably depends on the Firefox versions seen
1311)     in the wild. Question two: periodically people ask us to cycle through N
1312)     UserAgent strings rather than stick with one. Does this approach help,
1313)     hurt, or not matter? Consider: cookies and recognizing Torbutton users
1314)     by their rotating UserAgents; malicious websites who only attack certain
1315)     browsers; and whether the answers to question one impact this answer.
1316)     </li>
1317)     <li>How many bridge relays do you need to know to maintain
1318)     reachability? We should measure the churn in our bridges. If there is
1319)     lots of churn, are there ways to keep bridge users more likely to stay
1320)     connected?
1321)     </li>
1322)     </ol>

1323) 

1324)     <p>
1325)     <a href="<page about/contact>">Let us know</a> if you've made progress on any
1326)     of these!
1327)     </p>
1328)   </div>
1329)   <!-- END MAINCOL -->
1330)   <div id = "sidecol">
1331) #include "side.wmi"
1332) #include "info.wmi"
1333)   </div>
1334)   <!-- END SIDECOL -->
1335) </div>
1336) <!-- END CONTENT -->